Non-motorized treadmills do not have a motor to save the cost of the motor and save energy, so they have become more and more popular in recent years.
A conventional non-motorized treadmill, as disclosed in U.S. Pat. No. 9,005,085, comprises a closed loop treadmill belt which is wound around front and rear rollers. As shown in FIG. 27 of this patent, the rear roller is provided with a reluctance configuration for providing magnetic resistance.
As disclosed in U.S. Pat. No. 9,233,272 and Taiwan Utility Model Patent No. M530161, a non-motorized treadmill is provided with a magnetic member. The position of the magnetic member can be adjusted. The user can adjust the position of the magnetic member relative to a flywheel for adjusting the rotating resistance of the flywheel.
However, the resistance provided by a single resistance source is limited, and it cannot meet the requirement for a user who needs a high load for training. Especially, when the magnetic resistance is away from the flywheel, the resistance of the treadmill will be too small. As disclosed in Taiwan Utility Model Patent No. M530161, the reluctance control needs to cooperate with the returning of the elastic member. The elastic member may fatigue to affect its durability. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.